scholarly journals Feedforward Control Based on Error and Disturbance Observation for the CCD and Fiber-Optic Gyroscope-Based Mobile Optoelectronic Tracking System

Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 223 ◽  
Author(s):  
Yong Luo ◽  
Wei Ren ◽  
Yongmei Huang ◽  
Qiunong He ◽  
Qiongyan Wu ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Control Method ◽  
Feedforward Control ◽  
Tracking System ◽  
Sampling Rate ◽  
Low Frequency ◽  
Integration Time ◽  
Fiber Optic Gyroscope ◽  
Loop Control ◽  
Boresight Error

In the mobile optoelectronic tracking system (MOTS) based on charge-coupled device (CCD) and fiber-optic gyroscope (FOG), the tracking performance (TP) and anti-disturbance ability (ADA) characterized by boresight error are of equal importance. Generally, the position tracking loop, limited by the image integration time of CCD, would be subject to a non-negligible delay and low-sampling rate, which could not minimize the boresight error. Although the FOG-based velocity loop could enhance the ADA of the system, it is still insufficient in the case of some uncertain disturbances. In this paper, a feedforward control method based on the results of error and disturbance observation was proposed. The error observer (EOB) based on the CCD data and model output essentially combined the low-frequency tracking feedforward and closed-loop disturbance observer (DOB), which could simultaneously enhance the low-frequency TP and ADA. In addition, in view of the poor low-frequency performance of the FOG due to drift and noise that may result in the inaccuracy of the observed low-frequency disturbance, the FOG-based DOB was used to improve the relatively high-frequency ADA. The proposed method could make EOB and DOB complementary and help to obtain a high-precision MOTS, for in practical engineering, we give more attention to the low-frequency TP and full-band ADA. Simulations and experiments demonstrated that the proposed method was valid and had a much better performance than the traditional velocity and position double-loop control (VPDC).

Research on High Dynamic Target Electro-Optical Tracking Based Improved Robust Disturbance Observer

2011 ◽  
Vol 328-330 ◽  
pp. 2215-2219
Author(s):  
Xiang Yu ◽  
Zheng Hua Liu ◽  
Yan Ren
Keyword(s):  
Disturbance Observer ◽  
Control Method ◽  
Tracking System ◽  
Effective Means ◽  
Low Frequency ◽  
Optical Tracking ◽  
Control Technique ◽  
Frequency Noise ◽  
Optical Tracking System ◽  
Dynamic Target

The compound axis control technique is an effective means to improve the accuracy and bandwidth of high precision electro-optical tracking systems. However, traditional methods of lead and lag correction can not achieve ideal performance. The robust control method based on the disturbance observer (DOB) is introduced in this paper, and the method is applied to the electro-optical tracking system together with the Kalman Filter. Compared to the traditional method of lead and lag correction, the method based on DOB can inhibit high-frequency noise and compensate for low-frequency interference better, such as frictions, and achieve better precision finally.

Pre-Scheduled PID Control of a Solar Thermal Power Plant

1995 ◽  
Vol 17 (3) ◽  
pp. 132-142 ◽  
Author(s):  
A. Meaburn ◽  
F. M. Hughes
Keyword(s):  
Closed Loop ◽  
Feedforward Control ◽  
Thermal Power ◽  
Low Frequency ◽  
Outlet Temperature ◽  
Experimental Frequency ◽  
Efficient Operation ◽  
Loop Control ◽  
Tuning Method ◽  
Control Scheme

Efficient operation of a distributed solar collector field requires effective regulation of the outlet temperature. Control schemes utilising PI-based controllers, whether adaptive or fixed parameter, have been shown to be unsuitable for this application with a stable well-damped response only obtained at the expense of an unacceptably low speed of response. The reason for this is that collector fields possess low-frequency resonance dynamics which tend to restrict the bandwidth of such controllers. This paper examines the suitability and capability of PID controllers in this application area. Using experimental frequency response data, the Ziegler-Nichols tuning method for PID design is demonstrated to yield an unstable closed-loop system. However, by adopting a strategy which specifically aims to counter the adverse phase characteristics of the plant at resonance, good effective closed-loop control can be achieved. This is implemented as a pre-scheduled control scheme on the Acurex collector field at the Plataforma Solar de Almeria and tested in conjunction with a feedforward control scheme.

High-bandwidth fine tracking system for optical communication with double closed-loop control method

2019 ◽  
Vol 58 (02) ◽  
pp. 1
Author(s):  
Yukun Wang ◽  
Dayu Li ◽  
Rui Wang ◽  
Chengbin Jin ◽  
Shaoxin Wang ◽  
...  
Keyword(s):  
Optical Communication ◽  
Closed Loop ◽  
Control Method ◽  
Tracking System ◽  
Closed Loop Control ◽  
Loop Control ◽  
High Bandwidth

scholarly journals Soft Controllable Carbon Fibre-based Piezoresistive Self-Sensing Actuators

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 79
Author(s):  
Min Pan ◽  
Chenggang Yuan ◽  
Hastha Anpalagan ◽  
Andrew Plummer ◽  
Jun Zou ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Position Control ◽  
Control Method ◽  
Feedforward Control ◽  
The Body ◽  
Physical Contact ◽  
Sensing Element ◽  
Resistance Change ◽  
Soft Robots ◽  
Loop Control

Soft robots and devices exploit deformable materials that are capable of changes in shape to allow conformable physical contact for controlled manipulation. While the use of embedded sensors in soft actuation systems is gaining increasing interest, there are limited examples where the body of the actuator or robot is able to act as the sensing element. In addition, the conventional feedforward control method is widely used for the design of a controller, resulting in imprecise position control from a sensory input. In this work, we fabricate a soft self-sensing finger actuator using flexible carbon fibre-based piezoresistive composites to achieve an inherent sensing functionality and design a dual-closed-loop control system for precise actuator position control. The resistance change of the actuator body was used to monitor deformation and fed back to the motion controller. The experimental and simulated results demonstrated the effectiveness, robustness and good controllability of the soft finger actuator. Our work explores the emerging influence of inherently piezoresistive soft actuators to address the challenges of self-sensing, actuation and control, which can benefit the design of next-generation soft robots.

scholarly journals A New Disturbance Feedforward Control Method for Electro-Optical Tracking System Line-Of-Sight Stabilization on Moving Platform

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4350 ◽  
Author(s):  
Yunxia Xia ◽  
Qiliang Bao ◽  
Zidong Liu
Keyword(s):  
Control Method ◽  
Feedforward Control ◽  
Tracking System ◽  
Optical Tracking ◽  
Line Of Sight ◽  
Target Movement ◽  
Optical Tracking System ◽  
Pass Filter ◽  
Tracking Ability ◽  
Moving Platform

A feedforward control was proposed based on the decoupling of target movement and disturbance from gyro signals to improve the stabilization precision of line-of-sight (LOS) for an electro-optical tracking system (EOTS) on a moving platform. Signals measured by gyros mounted on gimbal consist of target movement and disturbance. To remove target movement and obtain middle and high frequency disturbance velocity, the gyro signals were filtered by a high pass filter. The disturbance velocity was integrated into the position signal and fed forward to the inner position loop of the fast steering mirror. A detailed analysis was provided to show the proposed approach, to improve disturbance suppression performance with only slight weakening of target tracking ability. The proposed feedforward control was effectively verified through a series of comparative simulations and experiments. Besides, the method was applied in a real ship-based project.

Simulation of Multi-Closed Loop Control With Feed Forward Control of Micro-Vibration Isolation Platform

2014 ◽  
Author(s):  
Qianqian Wu ◽  
Honghao Yue ◽  
Rongqiang Liu ◽  
Liang Ding ◽  
Zongquan Deng
Keyword(s):  
Vibration Isolation ◽  
Closed Loop ◽  
Control Method ◽  
Magnetic Levitation ◽  
Low Frequency ◽  
Closed Loop Control ◽  
Vibration Source ◽  
Feed Forward ◽  
Loop Control ◽  
Micro Vibration

Micro vibration in the ideal-zero gravity environments has complicated science experiment results. A magnetic levitation vibration isolation platform is needed to isolate the vibration source to provide acceptable acceleration level in low frequency range. The configuration of the Lorentz actuators is discussed in the paper. And the modeling of the transformation matrix from the force to the current is deduced. In order to generate desired force, the current is needed to predict precisely. To study the characteristics of the system, the single degree of freedom system is analyzed. A multi-closed loop control scheme is put forward to achieve vibration isolation control. To evaluate the effect of each control parameter, frequency domain analysis of the transfer function is simulated. In order to further increase the control effectiveness, a feed forward compensation control algorithm is added to control the vibration of cables that connect the upper platform and the base. By regulating these control parameters, bode curves can be obtained. Comparing the two methods, it can be concluded that the control method with feed forward compensation is better than the one without that.

Stabilization Control of Electro-Optical Tracking System With Fiber-Optic Gyroscope Based on Modified Smith Predictor Control Scheme

2018 ◽  
Vol 18 (19) ◽  
pp. 8172-8178 ◽  
Author(s):  
Wei Ren ◽  
Yong Luo ◽  
QiuNong He ◽  
Xi Zhou ◽  
Chao Deng ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Tracking System ◽  
Smith Predictor ◽  
Optical Tracking ◽  
Fiber Optic Gyroscope ◽  
Optical Tracking System ◽  
Stabilization Control ◽  
Control Scheme ◽  
Modified Smith Predictor

High Performance Drive Design for Hybrid Stepper Motors

2013 ◽  
Vol 706-708 ◽  
pp. 822-825
Author(s):  
Fa Hai Cao ◽  
Jian Ping Lv
Keyword(s):  
High Performance ◽  
Electronic Circuit ◽  
Control Method ◽  
Low Frequency ◽  
Loop Control ◽  
Driver Circuit ◽  
Stepper Motors ◽  
Automation Equipment ◽  
The Stability ◽  
Hardware Circuit

A new frequency-voltage modulation drive technique is proposed and analyzed for the use of stepping motor. Hardware circuit and the current compensation control method are given in the article. STM32 MCU control the PWM switch power, and combine L6384 to drive the MOSFET tube which consisting of H-bridge driver circuit. It simplifies the power drive electronic circuit. A high performance drive design about the best of drive curve is used through the analysis and study of the current closed-loop control. It will significantly improve the stability in low frequency and the torque frequency characteristic in high frequency, and the design can be used for high-power automation equipment.

Loop gain stabilizing with an all-digital automatic-gain-control method for high-precision fiber-optic gyroscope

2016 ◽  
Vol 55 (17) ◽  
pp. 4589 ◽  
Author(s):  
Yue Zheng ◽  
Chunxi Zhang ◽  
Lijing Li ◽  
Lailiang Song ◽  
Wen Chen
Keyword(s):  
High Precision ◽  
Fiber Optic ◽  
Control Method ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Loop Gain ◽  
Fiber Optic Gyroscope

The Attenuation of Very Low Frequency Brain Oscillations in Transitions from a Rest State to Active Attention

2009 ◽  
Vol 23 (4) ◽  
pp. 191-198 ◽  
Author(s):  
Suzannah K. Helps ◽  
Samantha J. Broyd ◽  
Christopher J. James ◽  
Anke Karl ◽  
Edmund J. S. Sonuga-Barke
Keyword(s):  
Brain Activity ◽  
Sampling Rate ◽  
Low Frequency ◽  
Future Research ◽  
Adhd Symptoms ◽  
Default Mode ◽  
Very Low Frequency ◽  
Wide Range ◽  
Interference Hypothesis ◽  
Mode Interference

Background: The default mode interference hypothesis ( Sonuga-Barke & Castellanos, 2007 ) predicts (1) the attenuation of very low frequency oscillations (VLFO; e.g., .05 Hz) in brain activity within the default mode network during the transition from rest to task, and (2) that failures to attenuate in this way will lead to an increased likelihood of periodic attention lapses that are synchronized to the VLFO pattern. Here, we tested these predictions using DC-EEG recordings within and outside of a previously identified network of electrode locations hypothesized to reflect DMN activity (i.e., S3 network; Helps et al., 2008 ). Method: 24 young adults (mean age 22.3 years; 8 male), sampled to include a wide range of ADHD symptoms, took part in a study of rest to task transitions. Two conditions were compared: 5 min of rest (eyes open) and a 10-min simple 2-choice RT task with a relatively high sampling rate (ISI 1 s). DC-EEG was recorded during both conditions, and the low-frequency spectrum was decomposed and measures of the power within specific bands extracted. Results: Shift from rest to task led to an attenuation of VLFO activity within the S3 network which was inversely associated with ADHD symptoms. RT during task also showed a VLFO signature. During task there was a small but significant degree of synchronization between EEG and RT in the VLFO band. Attenuators showed a lower degree of synchrony than nonattenuators. Discussion: The results provide some initial EEG-based support for the default mode interference hypothesis and suggest that failure to attenuate VLFO in the S3 network is associated with higher synchrony between low-frequency brain activity and RT fluctuations during a simple RT task. Although significant, the effects were small and future research should employ tasks with a higher sampling rate to increase the possibility of extracting robust and stable signals.

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